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pwm: add config_ms and config_percent.

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* Allows user to set both at the same time. Will reset to previous if
* period for duty cycle fails to write

Signed-off-by: Thomas Ingleby <thomas.c.ingleby@intel.com>
This commit is contained in:
Mark Ceisel
2014-09-01 12:18:01 +01:00
committed by Thomas Ingleby
parent a8bbd55562
commit 9cf6cad45a
3 changed files with 89 additions and 0 deletions
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20
api/mraa/pwm.h
View File

@@ -166,6 +166,26 @@ mraa_result_t mraa_pwm_owner(mraa_pwm_context dev, mraa_boolean_t owner);
*/
mraa_result_t mraa_pwm_close(mraa_pwm_context dev);
/**
* Set Both Period and DutyCycle on a PWM context
*
* @param dev The pwm context to use
* @param period represented in ms.
* @param duty dutycycle of the pwm signal.
* @return Result of operation
*/
mraa_result_t mraa_pwm_config_ms(mraa_pwm_context dev, int period, float duty);
/**
* Set Both Period and DutyCycle on a PWM context. Duty represented as percentage.
*
* @param dev The pwm context to use
* @param period represented in ms.
* @param duty duty percantage. i.e. 50% = 0.5f
* @return Result of operation
*/
mraa_result_t mraa_pwm_config_percent(mraa_pwm_context dev, int period, float duty);
#ifdef __cplusplus
}
#endif

21
api/mraa/pwm.hpp
View File

@@ -150,6 +150,27 @@ class Pwm {
else
return mraa_pwm_enable(m_pwm, 0);
}
/**
* Set the period and duty of a PWM object.
*
* @param period represented in ms.
* @param duty represnted in ms as float.
* @return Result of operation
*/
mraa_result_t config_ms(int period, float duty) {
return mraa_pwm_config_ms(m_pwm, period, duty);
}
/**
* Set the period and duty (percent) of a PWM object.
*
* @param period as represented in ms.
* @param duty percentage i.e. 50% = 0.5f
* @return Result of operation
*/
mraa_result_t config_percent(int period, float duty) {
return mraa_pwm_config_percent(m_pwm, period, duty);
}
private:
mraa_pwm_context m_pwm;
};

48
src/pwm/pwm.c
View File

@@ -301,3 +301,51 @@ mraa_pwm_owner(mraa_pwm_context dev, mraa_boolean_t owner_new)
dev->owner = owner_new;
return MRAA_SUCCESS;
}
mraa_result_t
mraa_pwm_config_ms(mraa_pwm_context dev, int ms ,float ms_float)
{
int old_dutycycle, old_period, status;
old_dutycycle = mraa_pwm_read_duty(dev);
old_period = mraa_pwm_read_period(dev);
status = mraa_pwm_write_duty(dev, 0);
if (status != MRAA_SUCCESS) {
return status;
}
status = mraa_pwm_period_us(dev, ms*1000);
if (status != MRAA_SUCCESS) {
mraa_pwm_write_duty(dev, old_dutycycle);
return status;
}
status = mraa_pwm_pulsewidth_us(dev, ms_float*1000);
if (status != MRAA_SUCCESS) {
mraa_pwm_write_duty(dev, old_dutycycle);
mraa_pwm_write_period(dev, old_period);
return status;
}
return MRAA_SUCCESS;
}
mraa_result_t
mraa_pwm_config_percent(mraa_pwm_context dev, int ms ,float percentage)
{
int old_dutycycle, old_period, status;
old_dutycycle = mraa_pwm_read_duty(dev);
old_period = mraa_pwm_read_period(dev);
status = mraa_pwm_write_duty(dev, 0);
if (status != MRAA_SUCCESS) {
return status;
}
status = mraa_pwm_period_us(dev, ms*1000);
if (status != MRAA_SUCCESS) {
mraa_pwm_write_duty(dev, old_dutycycle);
return status;
}
status = mraa_pwm_pulsewidth_us(dev, (ms*1000)*percentage);
if (status != MRAA_SUCCESS) {
mraa_pwm_write_duty(dev, old_dutycycle);
mraa_pwm_write_period(dev, old_period);
return status;
}
return MRAA_SUCCESS;
}